A  field experiment was carried at El-Gemmeiza Agric. Res. Station, El-Gharbihya Governorate, Egypt during the two successive summer seasons of 2017 and 2018 to evaluate the effect of  green fertilizer  (faba bean) and two  sources of potassium (mineral potassium sulphate (KS) 48 % K₂O)  or natural  feldspar (KF)  10.6 % K₂O  with  three  levels   50, 75 and 100 % of the recommended rate (RR) beside untreated  (control treatment)   on  growth, yield,  sepals  chemical constituents  and  the availability of macronutrients in soil after harvest of Roselle  plants (cv. Sabaheia 17)  under clay soil conditions. Fourteen treatments were carried out including the combinations of two levels of green fertilizers and six potassium fertilizes, while control treatments contain no fertilizers. A RCBD using a split plot was applied. Results revealed that growth and yield traits of Roselle plants including plant height, number of branches/plant, total dry weight/plant, fruit weight/plant, number of fruit/plant, seed weight/plant, sepals fresh and dry weight per plant and fed. and total yield of seeds/fed., leaf total chlorophyll and carotenoides, anthocyanin concentration, total carbohydrates, total acidity and P percentage in sepals were markedly improved when the green fertilizer combined with fertilizing with  75 % of the recommended Potassium rate (RR) in the form of feldspar (KF) (10.6 % K₂O)   equal 530.65 kg /fed., was applied.The interaction between green fertilizer and fertilizing with 100 % RR in the form of KF possessed the greatest availability of N, P, K, pH and EC in the soil after harvest.